Tumour lysis syndrome

Question 1

Define

Answer 1

DEFINITION: a group of metabolic abnormalities that can occur as a complication during treatment of cancer, where large amounts of tumour cells are lysed at the same time by treatment, releasing their contents into the bloodstream.

Question 2

Causes

Answer 2

It is caused by the sudden lysis of many tumour cells, which release their toxic contents into the blood stream

Occurs most commonly after treatment of lymphomas and leukaemias

Question 3

Risk factors

Answer 3

Tumour Characteristics - high cell turnover rate, rapid growth rate, high tumour bulk

Patient Characteristics - baseline serum creatinine, renal insufficiency, dehydration

Chemotherapy Characteristics - chemo-sensitive tumours (e.g. lymphoma) tends to have a higher risk

Question 4

Epidemiology

Answer 4

Tends to occur most commonly in patients with poorly differentiated lymphomas and leukaemias

Question 5

Symptoms

Answer 5

Hyperkalaemia

• K+ is mainly an intracellular ion
• Symptoms:
  
  • Arrhythmias
  • Severe muscle weakness and paralysis

Hyperphosphataemia

• Causes acute kidney failure because of deposition of calcium phosphate crystals in the kidney parenchyma

Hypocalcaemia

• Calcium precipitates to form calcium phosphate, so serum calcium drops
• Symptoms:
  
  • Tetany
  • Parkinsonism
  • Myopathy
  • Sudden mental incapacity

Hyperuricaemia

• Leads to gout

Lactic Acidosis

Question 6

Investigations

Answer 6

Check the levels of all the metabolites that are deranged:

• Potassium
• Phosphate
• Calcium
• Uric acid

Monitor for symptoms:

• Increased serum creatinine
• Arrhythmia
• Seizure